Vintage Synth Repair

hi Im new to the list!

My Roland sequencer 104, which has been fine until now just started
acting UP!!!

Im sure its just a tiny crack or something, but the first row of cv
just outputs a low voltage and the knobs do nothing, gate is being
sent, just no cv...

any ideas, I had it open and cleaned it really well, but I couldn't
see any cracked solder points or wires hangin ....

thanks!!

later,
ben
..

>>My Roland sequencer 104, which has been fine until now just started
> acting UP!!!
> 
> Im sure its just a tiny crack or something, but the first row of cv
> just outputs a low voltage and the knobs do nothing, gate is being
> sent, just no cv...
> 
> any ideas, I had it open and cleaned it really well, but I couldn't
> see any cracked solder points or wires hangin ....<<

can you read schemos? I have the diagram for this thing somewhere.
what I remember (haven't opened mine for ages) is that if the 2nd
column is working ok, it's probably the buffer amp or CV range switch
that's your problem. I will look for the schemo to send you.

duncan.

Hi Duncan,

Oh man, thanks a ton.....I personally cant read schemos but my best
friend is a tech so I'll get him to read them and help me fix this
baby... if you have the time and could upload them I would be
completely thrilled! thanks for replying! 

later,
ben
..



--- In vintagesynthrepair@yahoogroups.com, "duncan" <ferrograph@...>
wrote:

>
> >>My Roland sequencer 104, which has been fine until now just started
> > acting UP!!!
> > 
> > Im sure its just a tiny crack or something, but the first row of cv
> > just outputs a low voltage and the knobs do nothing, gate is being
> > sent, just no cv...
> > 
> > any ideas, I had it open and cleaned it really well, but I couldn't
> > see any cracked solder points or wires hangin ....<<
> 
> can you read schemos? I have the diagram for this thing somewhere.
> what I remember (haven't opened mine for ages) is that if the 2nd
> column is working ok, it's probably the buffer amp or CV range switch
> that's your problem. I will look for the schemo to send you.
> 
> duncan.
>

I'll look for them & email them to you- it's not a huge file, as I
recall.... in the meantime, enjoy exploring the notron! which one did
you get? mine (in bits & waiting for new switches after too many gigs)
is mk1 #45, bought new from latronic in 1996.
will buzz you the 104 schemo later.... might be able to upload it
here, even...

duncan/radio massacre international/london

encontrado!

I'm going to put them in the files section...

d.

hi duncan,

Much thanks on the roland 104 help... I have another guy (Peter from
Plan B) trying to help me fix a Steiner 151 sequencer with similar
problem....

I have a MK 1 notron, grey, serial # 10009 (does that mean #09?) ...
Bought it off ebay for 850$USD... it has been cut open (along the
edge) and reglued with super glue (white residue big clue), a number
of the "ball bearing" buttons have come unglued and roll out of their
holes if you turn it upside down...all the buttons and knobs work
although element 4's F5 knob is a little hard to turn ...
-- is this the sign of a dying encoder? or this one may have been
replaced? hmmm --

How do I know what operating system is inside? If it was cut open,
then perhaps they changed the chip? How can I tell what they replaced
on this thing? hehe... maybe Ill search the notron archives for this
serial number... yeah right! I search for previous owners who used
super glue! haha, detective work on something this rare is fun...

I have used the notron like 4 times (got it last week) but I really
think its great!

later,
ben
..



--- In vintagesynthrepair@yahoogroups.com, "duncan" <ferrograph@...>
wrote:

>
> I'll look for them & email them to you- it's not a huge file, as I
> recall.... in the meantime, enjoy exploring the notron! which one did
> you get? mine (in bits & waiting for new switches after too many gigs)
> is mk1 #45, bought new from latronic in 1996.
> will buzz you the 104 schemo later.... might be able to upload it
> here, even...
> 
> duncan/radio massacre international/london
>

>>I have a MK 1 notron, grey, serial # 10009 (does that mean #09?) ...
> Bought it off ebay for 850$USD... .....element 4's F5 knob is a
little hard to turn .......How do I know what operating system is
inside?<<

ok, first y'r 104. you are probably looking for a fault with one of
the 1458 op-amps (top right corner of the schemo) where the range
switches are, & where the column output is buffered. it's extremely
unlikely you have a fault before that stage that affects all of the
steps of the column. I think the 104, along with several other simple
step-sequencers of that era, used 12 steps rather than 16 because the
12-way switches were easy to get. the actual shift-registers are three
lumps of four, & it wouldn't have killed them to add another except
for trying to find a 16-way "last step" switch.

y'r mk1 notron is indeed an early one, & that's an extremely good
price- they have gone for three times that much in the past. I don't
know much about the subsequent software versions- I ignored the mk2
when it came out, thinking it quite hideous, & then lost touch with
dave & gerard. tom moravansky on the notron list (amongst others) is
the expert here. mine is cut open because I moved the "write" switch
to the rear of the case after one or two accidents... & as I
mentioned, it is in bits now because several of the tiny switches
failed. I have been contemplating mounting it on a 19" panel, & got as
far as having one made & buying 100+ mini toggle switches, but now I
have an octopus & it's making me think that the tactile nature of the
notron is too good to abandon. besides, I can probably get new
switches for it. 
one of my encoder wheels binds against the case slightly- maybe that
is the problem with yours? or against the mounting bracketry inside?
anyway, a failing encoder would usually manifest itself some other
way- it's unusual for them to fail by getting stiffer.

let me know how you get on with the roland, eh? :-)

duncan.